Estudio de mezclas biopoliméricas formuladas a partir de poliácido láctico y almidón de achira (Canna edulis)

Abstract

The research focused on the study of biopolymer blends based on polylactic acid (PLA), achira starch, polyvinyl alcohol (PVA) and glycerol. A 3 x 3 x 2 mixed factorial design was used to investigate the joint influence of 3 formulation variables: amount of PLA (36, 38 and 40%), PVA (3, 5 and 7%) and starch-glycerol ratio (1 and 0,7). The components were blended at 120 °C and 90 rpm for 20 min on a torque rheometer. Subsequently, the blended material was compression molded at 120 °C and 17,24 MPa into translucent films with uniform visual appearance. Thereafter, the tensile strength and elongation at break of the films were determined; results shown a directly proportional relation between these properties and PVA. By increasing the PLA, the tensile strength increased; however, this component does not have a significant statistical impact on elongation. According to FTIR data, blends spectra shown a combination of pure component peaks. Nevertheless, there were no shifts or different bands in the spectrograms to identify changes and interactions.